Hi All,

I'm looking for some help and advice, as well as possibly some new ideas. I am 80% finished designing my latest masterpiece, a relatively slow flying 3D type jet and I am a bit stuck as to the tailerons.

First of all i would like be able to mimic the airbraking effect that 1:1's use with LOTS of deflection, so what is the best way to get max movement??

Secondly, the pivot point. what do people use as a pivot, concentric tubes??? what sizes??

Any help appreciated.

PS It's being designed in CAD so i can change things easily and CNC cut all the parts

The air brake effect is not from the tailerons, it is from the pitch up of the fuselage at lower throttle settings. You wanna be careful about too much throw in a taileron/(full flying stab) setup. It'll get ya to gallopin' LOL (And changin yer drawers)

hi terry,

im used to lots of movement, not all my own doing!!!!. the effect i was looking for was where (in full size) they use a lot of down elevator on the ground on the landing roll to slow down, about 80 degrees ish.

cheers

One thing to keep in mind, that doesn't effect the full scale guys, is the tail lifting and taking weight off the mains. This will have an adverse effect on braking and ground handling if the landing is a little fast.

hi rcmigpilot,

as i said, i want it more for effect than to use it as an airbrake. i fully understand that the model will not have enought mass to us it as an airbrake. i want this effect because at all the 1:1 airshows ive been to, the most spectacular displays have been from the aircraft that have the most movement on the tailerons, and if i can recreate this effect in miniture it would be great.

its not all about how well it flys, its also about its presence on the ground

Got the idea now. Kinda like opening canopies, doesn't do squat for the flight but looks really cool when they pop open on the taxi back. Have you thought of setting up a mix on a switch that overdrives the servos and causes them to move farther than during normal control? I think my JR will let me program a mix in and set travel up to 150%.

I havent got that far yet!!

all im looking for atm is a substansial way of making the pivot/hinge for the tailerons that will give me the possibility of excessive movement

A few thoughts...
I have an F-16 that has maybe +- 35-38 degrees of travel.

Use a relatively long moment arm on the servo and surface to minimise the affects of slop

Use a high ATV to make your servo work through a long angular range... maybe 125%

A tube makes a good pivot as it is stiffer in bending and twisting than a solid rod per unit weight. 5/16" diameter steel is a good starting point depending on the size and weight of the model.

Close fitting bushings are OK... ball bearings are better.

Stiffeness of all mountings and linkages is key.

opintions may vary, but 25% MAC is a good place to start, and static balancing is a plus....

David

Do all that David said, but in addition, use a programmable servo and set the end points to greater than the usual +/- 45 degrees to get more throw with no loss of torque.